Studies on the Use of Locally Available Renewable Seaweed Wastesfrom Cox’s Bazar and Saint Martin as Compost Organic FertilizerResources

Abstract

This study evaluates the potential of Hypnea species, a red seaweed prevalent along the coasts of Cox’s Bazar and Saint Martin, Bangladesh, as a sustainable source for organic compost fertilizer. Hypnea’s nutrient profile includes high levels of potassium (K), nitrogen (N), and phosphorus (P), alongside micronutrients such as iron (Fe), zinc (Zn), and manganese (Mn), as well as bioactive compounds like carrageenan, auxins, and cytokinin’s. These characteristics make it beneficial for enhancing soil health, promoting plant growth, and increasing crop yield. The composting process for Hypnea is efficient, marked by rapid biodegradation and active microbial involvement, resulting in nutrient rich humus that enhances soil structure, moisture retention, and pH balance, while improving plant resistance to stressors like drought and salinity. A six-month field experiment conducted in the Khasia farming community of Sreemangal
assessed three treatments: T1 (control with standard farming practices), T2 (25g of seaweed-based compost per support tree), and T3 (50g of seaweed-based compost per support tree). The highest yield was observed in T3, with an average of 2880 betel leaves plucked per day, significantly surpassing T1 and T2, which both recorded 2780 leaves. ANOVA analysis confirmed the statistical significance of these results (F-statistic: 14822.79; p-value ≈ 8.84 × 10^-42). The findings underscore that applying 50g of seaweed-based compost per tree significantly boosts betel leaf yield, demonstrating the practice’s economic viability by reducing reliance on chemical fertilizers and cutting agricultural costs, aligning with sustainable development goals and the blue economy framework. Challenges such as salinity management, seasonal availability, and contamination prevention are noted, with recommendations for future research including optimization of composting techniques and long-term trials. This study advocates for integrating traditional knowledge with modern composting to foster sustainable, productive agricultural practices.